I was wondering if there is any way to configure your default message "DocumentParser::FetchDocument - Parse error in file: received event: error.badfetch" to custom "I'm sorry, but we're currently experiencing issues. Please try your call again later." I think the second will be more appropriate to hear for our customers.

To change the message for badfetch errors, you can catch the error.badfetch event in your root document and play the message you would rather play than the default upon catching this event. An example would be as follows

Here, if nonexistant_page.vxml either doesn't exist or has syntax errors, when your application tries to go to nonexistant_page.vxml the badfetch event will be caught by the handler in the root document, and your custom error message will be played. For more information on the root document and global catch handlers, you can reference our docs here: http://www.plumvoice.com/docs/dev/developer_reference:rootdocument

I have another question regarding the error message configuration. How we can configure default message in case of some network issues? For example, currently what error message will be played if for some reason the network went down and "root.vxml" can't be accessed?

If you are concerned about your root document being inaccessible we would recommend using a scratchpad application for the error handling. You can set up a scratchpad that makes a request to your start_url. If it receives a response it can proceed to execute your application as usual. If it receives an error you can proceed with the catch event tag we outlined previously, which will play your custom message to the caller.